I'm on a Dell Optiplex GX620 with GMA 950 and MATE is the only DE I tried that shows me minimizing window frames when I click minimize instead of a smooth transition. Also there's no effects when I click on a panel icon. How do I fix that?

When I add app shortcuts to the panel, they're stuffed in between the menu and the spacer next to the show desktop icon. But after a reboot they're in the running apps space which aren't shown anymore until I delete the icons.